Extrusion prevention ring for a liner hanger system

ABSTRACT

In accordance with some embodiments of the present disclosure, an extrusion prevention ring for a liner hanger system is disclosed. The liner hanger includes an elongate body, a first groove in the elongate body, a first extrusion prevention ring disposed about the elongate body and selectively deformable between a first configuration, where the first extrusion prevention ring is moveable along the length of the elongate body, and a second configuration, where the first extrusion prevention ring is deformed to be received within the first groove, and a seal member disposed about the elongate body and adjacent to the first extrusion prevention ring when the first extrusion prevention ring is in the second configuration, the first extrusion prevention ring configured to prevent movement of the seal member along the length of the elongate body.

TECHNICAL FIELD

The present disclosure relates generally to hydrocarbon recoveryoperations and, more particularly, to an extrusion prevention ring for aliner hanger system.

BACKGROUND

When performing subterranean operations, a wellbore is typically drilledand completed to facilitate removal of natural resources (e.g.,hydrocarbons or water) from a subterranean formation. Often, once awellbore is drilled, a casing string may be inserted into the wellbore.Cement may be used to install the casing string in the wellbore andprevent migration of fluids in the annulus between the casing string andthe wellbore wall. In certain implementations, the casing string may bemade of heavy steel.

Once an upper portion of the wellbore has been drilled and cased, it mayhe desirable to continue drilling and to line a lower portion of thewellbore with a liner lowered through the upper cased portion of thewellbore. Liner hangers may be installed in the lower end of apreviously installed casing string and may be used to mechanicallysupport an upper end of the liner. Additionally, liner hangers may beused to seal the liner to the casing string.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present disclosure and itsfeatures and advantages, reference is now made to the followingdescription, taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 illustrates an elevation view of an example embodiment of adrilling system;

FIG. 2A illustrates a cross-sectional view of an example embodiment of aliner hanger featuring seal members and extrusion prevention rings;

FIG. 2B illustrates a cross-sectional view of the liner hanger shown inFIG. 2A in an expanded configuration;

FIG. 3A illustrates a side view of an exemplary extrusion preventionring;

FIG. 3B illustrates a section view of the exemplary extrusion preventionring shown in FIG. 3A; and

FIG. 3C illustrates a cross-sectional view of the profile of theexemplary extrusion prevention ring shown in FIG. 3A.

DETAILED DESCRIPTION

The present disclosure describes an extrusion prevention ring for usewith a liner hanger system. During a subterranean operation, a liner maybe placed in a wellbore to line a portion of the wellbore. The liner maybe suspended from a liner hanger coupled to a casing string in thewellbore. The liner hanger may include seal members surrounding theouter perimeter of the body of the liner hanger that anchor the linerhanger to the casing string and provide an annular seal between theliner hanger and the casing string. Additionally, the liner hanger mayhave extrusion prevention rings located adjacent to each seal memberthat encircle the outer perimeter of the body of the liner hanger. Theextrusion prevention rings may provide additional anchoring capacitybetween the liner hanger and the casing string and provide a sealbetween the liner hanger and the casing string. The extrusion preventionrings may also maintain the position of the seal members. For example,when the liner hanger is in contact with the casing string, the sealmembers may spread due to the compression of the seal members betweenthe casing string and the liner hanger. The extrusion prevention ringmay prevent the spread and maintain the thickness of the seal members.The extrusion prevention rings may be coupled to the outer perimeter ofthe liner hanger without requiring an increase in the weight or thethickness of the walls of the liner hanger. Accordingly, a system andmethod of use may be designed in accordance with the teachings of thepresent disclosure to increase the anchoring and sealing capacity of theliner hanger, improve the efficiency, and reduce the cost of thesubterranean operation. Embodiments of the present disclosure and theiradvantages are best understood by referring to FIGS. 1 through 3, wherelike numbers are used to indicate like and corresponding parts.

FIG. 1 illustrates an elevation view of an example embodiment of adrilling system. Drilling system 100 may include well surface or wellsite 106. Various types of drilling equipment such as a rotary table,drilling fluid pumps and drilling fluid tanks (not expressly shown) maybe located at well site 106. For example, well site 106 may includedrilling rig 102 that has various characteristics and featuresassociated with a “land drilling rig.” However, downhole drilling toolsincorporating teachings of the present disclosure may be satisfactorilyused with drilling equipment located on offshore platforms, drill ships,semi-submersibles and drilling barges (not expressly shown).

Drilling system 100 may also include drill string 103 associated withdrill bit 101 that may be used to form a wide variety of wellbores orbore holes such as generally vertical wellbore 114 a or generallyhorizontal wellbore 114 b or any combination thereof. Variousdirectional drilling techniques and associated components of bottom holeassembly (BHA) 120 of drill string 103 may be used to form horizontalwellbore 114 b. For example, lateral forces may be applied to BHA 120proximate kickoff location 113 to form generally horizontal wellbore 114b extending from generally vertical wellbore 114 a. The term“directional drilling” may be used to describe drilling a wellbore orportions of a wellbore that extend at a desired angle or angles relativeto vertical. The desired angles may be greater than normal variationsassociated with vertical wellbores. Direction drilling may also bedescribed as drilling a wellbore deviated from vertical. The term“horizontal drilling” may be used to include drilling in a directionapproximately ninety degrees (90°) from vertical.

BHA 120 may be formed from a wide variety of components configured toform wellbore 114. For example, components 122 a, 122 b, and 122 c ofBHA 120 may include, but are not limited to, drill bits (e.g., drill bit101), coring bits, drill collars, rotary steering tools, directionaldrilling tools, downhole drilling motors, reamers, hole enlargers, orstabilizers. The number and types of components 122 included in BHA 120may depend on anticipated downhole drilling conditions and the type ofwellbore that will be formed by drill string 103 and rotary drill bit101. Drill bit 101 may include one or more blades 126 that may bedisposed outwardly from exterior portions of rotary bit body 124 ofdrill bit 101. Drill bit 101 may rotate with respect to bit rotationalaxis 104 in a direction defined by directional arrow 105. BHA 120 mayalso include various types of well logging tools (not expressly shown)and other downhole tools associated with directional drilling of awellbore. Examples of logging tools and/or directional drilling toolsmay include, but are not limited to, acoustic, neutron, gamma ray,density, photoelectric, nuclear magnetic resonance, rotary steeringtools, and/or any other commercially available well tool.

Wellbore 114 may be defined in part by casing string 110 that may extendfrom well surface 106 to a selected downhole location, Portions ofwellbore 114, as shown in FIG. 1, that do not include casing string 110may be described as “open hole.” Various types of drilling fluid may bepumped from well surface 106 downhole through drill string 103 toattached drill bit 101. “Uphole” may be used to refer to a portion ofwellbore 114 that is closer to well surface 106 and “downhole” may beused to refer to a portion of wellbore 114 that is further from wellsurface 106. The drilling fluids may be directed to flow from drillstring 103 to respective nozzles passing through rotary drill bit 101.The drilling fluid may be circulated uphole to well surface 106 throughannulus 108. In open hole embodiments, annulus 108 may be defined inpart by outside diameter 112 of drill string 103 and inside diameter 118of wellbore 114. In embodiments using casing string 110, annulus 108 maybe defined by outside diameter 112 of drill string 103 and insidediameter 111 of casing string 110.

Casing string 110 may be made of any suitable material that iscompatible with the conditions in wellbore 114, such as steel. In sonicembodiments, open hole portions of wellbore 114 may be lined with liner130. Liner 130 may be used to line or case the open hole portion ofwellbore 114. In some embodiments, cement may be placed between liner130 and inner diameter 118 of wellbore 114. Liner 130 may be installedin wellbore 114 through the use of drill string 103. Drill string 103may include a releasable collet (not expressly shown) by which drillstring 103 can support and rotate liner 130 as liner 130 is placed inwellbore 114.

Liner hanger 132 may be attached to the upper end of, or formed as anintegral part of liner 130. Liner hanger 132 may have an elongate bodythat may include one or more seal members 134 surrounding liner hanger132 along the axial length of liner hanger 132. When liner hanger 132 isinstalled in wellbore 114, seal member 134 may anchor liner hanger 132to casing string 110 and may create a fluid-tight and pressure-tightseal between liner hanger 132 and casing string 110. Seal members 134may be made of any suitable elastomeric material. The elastomericmaterial may be formed of compounds including, but not limited to,natural rubber, nitrile rubber, hydrogenated nitrile, urethane,polyurethane, fluorocarbon, perflurocarbon, propylene, neoprene, hydrin,etc. While three seal members 134 are depicted for illustrativepurposes, any number of seal members 134 may be used.

As described in further detail in FIGS. 2A and 2B, liner hanger 132 maybe designed such that it may be plastically deformed downhole inwellbore 114 from a contracted position to an expanded position. In thecontracted position, the outer diameter of liner hanger 132, defined bythe outer diameter of seal members 134, may be smaller than innerdiameter 111 of casing string 110 such that liner hanger 132 may belowered into wellbore 114. As described in further detail with respectto FIGS. 2A and 2B, when liner hanger 132 is positioned downhole inwellbore 114, expansion cones located on drill string 103 may expandliner hanger 132 into the expanded configuration, where the outerdiameter of liner hanger 132 expands such that seal members 134 are incontact with inner diameter 111 of casing string 110. When seal members134 are in contact with casing string 110, seal members 134 may providea seal against casing string 110 and support the weight of liner 130.

When seal member 134 is in contact with inner diameter 111 of casingstring 110, seal member 134 may be compressed between liner hanger 132and casing string 110. The pressure created by the compression of sealmember 134 may cause seal member 134 to spread out along the perimeterof liner hanger 132 and the thickness of seal member 134 may decrease.Additionally, the weight of liner 130 may cause seal member 134 tomigrate from one location to another along liner hanger 132. Themigration and/or spreading of seal member 134 may decrease the abilityof seal member 134 to provide sealing and anchoring functions for linerhanger 132. Therefore, liner hanger 132 may include one or moreextrusion prevention rings (e.g., extrusion prevention rings 246 shownin FIGS. 2A and 2B) located on the sides of seal member 134 to maintainthe position of seal member 134 and prevent seal member 134 fromspreading and/or migrating along the outer perimeter of liner hanger132. FIG. 2A illustrates a cross-sectional view of an example embodimentof a liner hanger including seal members and extrusion prevention rings.Liner hanger 232 may be used to suspend liner 230 in a wellbore (e.g.,wellbore 114 shown in FIG. 1). Liner hanger 232 may be coupled to casingstring 210 via one or more seal members 234 and/or one or more extrusionprevention rings 246. Liner hanger 232 may be made of any suitableductile material that is compatible with the conditions in the wellbore,such as steel or a suitable corrosion resisting alloy (CRA), that allowsliner hanger 232 to be plastically deformed from an originalconfiguration to an expanded configuration.

Liner hanger 232 may further include a polished bore receptacle, or tieback receptacle, 236 coupled to the upper end of liner hanger 232. Inone embodiment, polished bore receptacle 236 may be coupled to linerhanger 232 by a connector, such as threaded joint 238. The inner bore ofpolished bore receptacle 236 may be smooth and machined to closetolerance to permit drill strings, production tubing, and/or any othersuitable subterranean tool to he connected to liner 232 with afluid-tight and pressure-tight connection. For example, productiontubing may be connected to polished bore receptacle 236 and used to pumpfracturing fluid at high pressure down a without exposing casing string210 to the fracturing pressure. While polished bore receptacle 236 isshown as above liner hanger 232 in FIG. 2A, alternatively polished borereceptacle 236 may be located below liner hanger 232.

The outer diameter of liner 230 may be as large as possible while stillallowing liner 230 to he lowered through casing string 210.Additionally, while liner hanger 232 is in the original configuration,the outer diameter of liner hanger 232 may be defined by the outerdiameter of the seal members 234 such that the outer diameter of linerhanger 232 is approximately the same as the outer diameter of liner 230.

During assembly of liner hanger 232, one or more grooves 248 may beformed in the outer perimeter of liner hanger 232. Groove 248 may beformed by any suitable manufacturing process such as machining. Groove248 may be placed along the outer perimeter of liner hanger 232 suchthat the spacing of grooves 248 along the axial length of liner hanger232 corresponds with the placement of one or more seal members 234. Forexample a first groove 248 may be machined along the outer perimeter ofliner hanger 232 at a first axial position of liner hanger 232 and asecond groove 248 may be machined along the outer perimeter of linerhanger 232 at a second axial position along liner hanger 232 where thefirst and second axial positions correspond to the edges of seal member234.

Liner hanger 232 may further include one or more extrusion preventionrings 246 placed over one or more grooves 248. Extrusion prevention ring246 may he made of any suitable ductile material that withstands theconditions in the wellbore and has a high yield strength and a highelongation, such as aluminum, steel, or stainless steel. For example,extrusion prevention ring 246 may be made of a stainless steel, such asAISI 316 stainless steel. Extrusion prevention ring 246 may be designedto provide a predetermined contact stress when expanded into casing 210.

Extrusion prevention ring 246 may be installed on the outer perimeter ofliner hanger 232 by sliding extrusion prevention ring 246 over an end ofliner hanger 232 until extrusion prevention ring 246 is at apredetermined position e.g., over groove 248). After extrusionprevention ring 246 is placed over groove 248, extrusion prevention ring246 may be compressed and plastically deformed to fit snugly againstgroove 248 along the outer diameter of liner hanger 232. Extrusionprevention ring 246 may be compressed by any suitable means of deformingmetal, such as through the use of a piston-pressure device or a crimpingtool. Liner hanger 232 may include extrusion prevention rings 246located over each groove 248. The placement of extrusion preventionrings 246 and grooves 248 may be such that an extrusion prevention ring246 is placed adjacent to one or both sides of one or more seal members234 along the axial length of liner hanger 232.

Groove 248 may have edges 250 to maintain the placement of extrusionprevention ring 246 when extrusion prevention ring 246 is placed overgroove 248. In some embodiments, the shape of groove 248 may mirror theshape of extrusion prevention ring 246. For example, in FIGS. 2A and 28.groove 248 is trapezoidal shaped, corresponding to the trapezoidal shapeof the inner surface of extrusion prevention ring 246. When the shape ofgroove 248 mirrors the shape of inner surface 364, groove 248 mayprovide structural support for extrusion prevention ring 246. In otherembodiments, the shape of groove 248 may not mirror the shape ofextrusion prevention ring 246 or may be a complementary shape to theshape of extrusion prevention ring 246. While groves 248 are shown inFIGS. 2A and 2B has having a trapezoidal shape, grooves 248 may be anysuitable shape such as circular, square, or rectangular. Grooves 248 maybe designed to contain extrusion prevention ring 246 to prevent damageto extrusion prevention ring 246 during placement of liner hanger 232 inthe wellbore. The design of groove 248 may additionally provide supportfor extrusion prevention ring 246 to prevent axial movement of extrusionprevention ring 246 during expansion of liner hanger 232 and while linerhanger 232 is used during the subterranean operation.

Once extrusion prevention rings 246 are installed on liner hanger 232,one or more seal members 234 may be formed over the outer diameter ofliner hanger 232. Seal member 234 may be positioned such that one ormore extrusion prevention rings 246 are located on the sides of sealmember 234. Seal member 234 may be made of any suitable elastomericmaterial that may be compatible with the conditions in the wellbore,such as an elastomeric material (e.g., rubber), ductile metals (e.g.,AISI type 316L stainless steel), or other polymeric materials.

Seal members 234 may be spaced along the axial length of liner hanger232, surrounding the outer perimeter of liner hanger 232 according tothe planned use of liner hanger 232. For example, in high temperature,high pressure (referred to as “HPHT”) subterranean operations, linerhanger 232 may include a greater number of seal members 234 than thenumber of seal members 234 used for a non-high temperature, highpressure subterranean operation. The distance between each seal member234 may be determined such that any deformation induced in casing string210 by the force exerted by seal members 234 may be minimized and/orisolated and the force of seal member 234 may be distributed alongcasing string 210. Additionally, the distance between seal members 234may be selected to maximize the hanging capacity of seal members 234.The hanging capacity is the maximum downward force seal member 234 maycarry without causing liner hanger 232 to move relative to casing string210. The distance between seal members 234 may be based on any suitablefactor, such as the outer diameter of liner hanger 234, the thickness ofthe wall of liner hanger 234, the inner diameter of casing string 210,the thickness of casing string 210, and/or the weight of liner 230. Forexample, the distance between the seal members may be smaller when theweight of liner 230 is heavier. The length of liner hanger 234 may limitthe number of seal members 234 that may be placed on liner hanger 234.

Seal member 234 may be positioned at any axial location along the outerperimeter of liner hanger 232. The placement of one or more seal members234 may be based on any suitable design parameter such as the weight ofliner 230 suspended from liner hanger 232.

FIG. 2B illustrates a cross-sectional view of the liner hanger shown inFIG. 2A in an expanded configuration. During installation of linerhanger the wellbore, liner hanger 232 may be deployed on a setting toolto provide the axial force required to expand liner hanger 232 (e.g., asetting tool on drill string 103 shown in FIG. 1). When liner hanger 232is positioned in casing string 210, fluid pressure applied to the drillstring and liner hanger 232 may be used to drive expansion cone 240downward through liner hanger 232 to expand and plastically deform linerhanger 232 to the expanded configuration where one or more seal members234 are forced into contact with casing string 210. An alternate settingmethod may be used to deliver the setting force, such as a mechanicallyor electronically activated tool. The contact between seal member 234and casing string 210 may anchor liner hanger 232 to casing string 210and may provide a pressure-tight and/or fluid-tight seal between linerhanger 232 and casing string 210. After liner hanger 232 is expanded,expansion cone 240 may he removed from liner hanger 232, throughpolished bore receptacle 236 and out of the wellbore.

When liner hanger 232 is expanded in the wellbore, seal members 234 maycontact casing string 210 and may couple liner hanger 232 to casingstring 210. Additionally, extrusion prevention ring 246 may expand withliner hanger 232. During expansion, extrusion prevention ring 246 may beplastically deformed and may maintain the position of extrusionprevention ring 246 relative to seal member 234 to maintain the positionof seal member 234 along the axial length of liner hanger 232.

Seal member 234 may be held in place by one or more extrusion preventionrings 246. Extrusion prevention ring 246 may maintain the position ofseal members 234 and prevent seal members 234 from migrating along theouter diameter of liner hanger 232 and/or spreading while seal members234 support the weight of liner 230 and anchor liner hanger 232 tocasing string 210. Extrusion prevention ring 246 may be placed at one orboth sides of seal member 234. Extrusion prevention ring 246 may be acircular ring that extends along the outer perimeter of liner hanger 232at a predetermined axial location (e.g., at a side of seal member 234).

In addition to maintaining the position of seal member 234, in someembodiments extrusion prevention ring 246 may provide additionalanchoring capability for liner hanger 232 by forming a metal to metalcontact with casing string 210. Extrusion prevention ring 246 may alsoprovide a seal between liner hanger 232 and casing string 210. The useof extrusion prevention ring 246 and seal member 234 on liner hanger 232may enhance the anchoring and sealing of liner hanger 232 with casingstring 210 when compared to a liner hanger 232 having seal members 234alone. Additionally, the use of extrusion prevention ring 246 mayprovide redundant anchoring and pressure integrity for liner hanger 232in the event that a seal member 234 is damaged during installation ofliner hanger 232 in the wellbore.

While liner hanger 232 is shown in FIGS. 2A and 2B as having three sealmembers 234, liner hanger 232 may have any number of seal members 234.The number of seal members 234 may be based on the characteristics ofthe subterranean operation, such as the weight of liner 230 suspendedfrom liner hanger 232. Additionally, while liner hanger 232 is shown ashaving six extrusion prevention rings 246, liner hanger 232 may have anynumber of extrusion prevention rings 246. While extrusion preventionrings 246 are shown as having a flat top, extrusion prevention rings 246may have any suitable shape such as pointed, spiked, or curved.

FIG. 3A illustrates a side view of an exemplary extrusion preventionring. Extrusion prevention ring 346 may be placed around the outerdiameter of a liner hanger (e.g., liner hanger 232 shown in FIGS. 2A and2B) and may maintain the position of one or more annular seals.Additionally, extrusion prevention ring 346 may provide metal-to-metalcontact between extrusion prevention ring 346 and a casing string (e.g.,casing string 210) to anchor and seal the liner hanger to the casingstring.

The diameter of extrusion prevention ring 346, shown as “d” in FIG. 3A,may be any suitable diameter corresponding to the outer diameter of theliner hanger. Liner hangers may have different sizes depending on theparticular application and the size of extrusion prevention ring 346 maycorrespond to the diameter of a liner hanger. For example, the diametermay be slightly larger than the unexpanded outer diameter of the linerhanger such that extrusion prevention ring 346 may slide over the linerhanger during the assembly process, as described with reference to FIGS.2A and 2B. Extrusion prevention ring 346 may be manufactured through anysuitable process, such as casting and extruding. Extrusion preventionring 346 may be made of any suitable ductile material that may allowextrusion prevention ring 346 to be deformed from an originalconfiguration, to a deformed configuration, and to an expandedconfiguration. Extrusion prevention ring 346 may also be made of amaterial that withstands the conditions in the wellbore and has a highyield strength and a high elongation, such as aluminum, steel, orstainless steel. For example, extrusion prevention ring 246 may be madeof a stainless steel, such as AISI 316 stainless steel.

Extrusion prevention ring 346 may be placed along the outer perimeter ofthe liner hanger such that extrusion prevention ring 346 protrudes fromthe outer perimeter of the liner hanger and is slidable along the lengthof the liner hanger and rotatable about the liner hanger. Afterextrusion prevention ring 346 is installed over a groove in the linerhanger (e.g., groove 248 shown in FIGS. 2A and 2B), extrusion preventionring 346 may be deformed, or crimped, against the groove. In thecontracted configuration, extrusion prevention ring 346 may be seated inthe groove and the diameter of extrusion prevention ring 346 may bedecreased relative to an original configuration. Extrusion preventionring 346 may be deformed by any suitable deformation methods, such asthrough the use of a piston pressure device or a crimping tool. Afterthe liner hanger is positioned in the wellbore and expanded wherebyextrusion prevention ring 346 may also be expanded with the linerhanger. In the expanded configuration, top surface 354 may be in contactwith the casing string and the diameter of extrusion prevention ring 346may be increased relative to a deformed or crimped configuration and/oran original configuration.

FIG. 3B illustrates a section view of the exemplary extrusion preventionring shown in FIG. 3A. Extrusion prevention ring 346 is shown sectionedalong section A-A shown in FIG. 3A. FIG. 3C illustrates across-sectional view of the profile of the exemplary extrusionprevention ring shown in FIGS. 3A and 3B. The profile of extrusionprevention ring 346 may be any suitable profile that maintains theposition of a seal member and provides a contact surface between a linerhanger and a casing string of a wellbore.

In some embodiments, extrusion prevention ring 346 may provide ametal-to-metal seal between the liner hanger and the casing string. Whenextrusion prevention ring 346 is in the expanded configuration, topsurface 354 of extrusion prevention ring 346 may be flat to provide amore effective contact surface between the liner hanger and the casingstring than an extrusion prevention ring 346 with a pointed or spikedtop surface 354. For example, the casing string e.g., casing string 110shown in FIG. 1) may have surface variations such that the surface ofthe casing string is not even and/or smooth and top surface 354 mayprovide a larger surface area to contact the casing string to bridge anyvariations in the surface of the casing string. Additionally, when topsurface 354 is flat, top surface 354 may provide a higher load capacityfor supporting the weight of the liner hanger and the liner due to thelarger contact area between extrusion prevention ring 346 and the casingstring provided by top surface 354.

In some embodiments, top surface 354 may be textured to provide a highercoefficient of friction between extrusion prevention ring 346 and theinner diameter of the casing string. For example, top surface 354 may bethreaded, knurled, sandblasted, serrated, or otherwise textured toeliminate the smoothness of top surface 354. The texturing of topsurface 354 may be such that as extrusion prevention ring 346 isdeformed or expanded from the original configuration to the deformedconfiguration and/or expanded configuration, the texturing of topsurface 354 remains intact.

In some embodiments, the profile of extrusion prevention ring 346 may besymmetrical such that angle 356 a is approximately the same as angle 356b. In other embodiments, the surface geometry of extrusion preventionring 346 may he asymmetrical such that angle 356 a is different fromangle 356 b. Angles 356 a and 356 b may be selected such that after theliner hanger and extrusion prevention ring 346 are expanded in thewellbore, profile 358 of extrusion prevention ring 346 may remainapproximately normal to the body of the liner hanger. For example,angles 356 a and 356 b may be any suitable angle between approximately30° to approximately 70°.

Top surface 354 may have width 360 that may be selected based on therequirements of the subterranean operation. For example, width 360 maybe based on the predetermined surface area designed to contact thecasing string to support the weight of the liner hanger and the liner.Width 360 may be selected to maintain a suitable width of extrusionprevention ring 346 such that in the expanded state, extrusionprevention ring 346 maintains the position of one or more seal membersalong the outer perimeter of the liner hanger.

Height 362 (e.g., the difference between the outer diameter and theinner diameter of extrusion prevention ring 346) may be configured suchthat the outer diameter of extrusion prevention ring 346 may be similarto the outer diameter of a seal member. For example, as shown in FIGS.2A and 2B, the outer diameters of extrusion prevention ring 246 and sealmember 234 extend from the outer perimeter of liner hanger 232 byapproximately the same amount. In other embodiments, height 362 may besuch that the outer diameter of extrusion prevention ring 346 may beless than or greater than the outer diameter of the seal members.

Height 362 may be based on a function of an amount of possiblecompression of the seal member when the seal member is in contact withthe casing string. For example, height 362 may he a distance from theouter perimeter of the liner hanger such that when the seal member iscompressed, the outer diameter of extrusion prevention ring 346 may beapproximately the same as the outer diameter of the compressed sealmember. Height 362 may result in both the seal member and extrusionprevention ring 346 contacting the casing string which may allow theliner hanger to support a greater weight than a liner hanger where onlythe seal member contacts the casing string or a liner hanger where onlyextrusion prevention ring 346 contacts the casing string. Extrusionprevention ring 346 may provide mechanical support for the liner and theliner hanger.

Any number of extrusion prevention rings 346 may be placed along theaxial length of the liner hanger. The number of extrusion preventionrings 346 placed along the axial length of the liner hanger may be basedon any suitable consideration, such as the number of seal members placedon the liner hanger, the weight of the liner suspended from the linerhanger, or the predetermined anchor and/or sealing capacity of extrusionprevention rings 346. Each of extrusion prevention rings 346 may provideanchor capability and sealing capability for the liner hanger, as wellas act as a retainer for the seal member when the seal member iscompressed between the casing string and the liner hanger.

Extrusion prevention ring 346 may provide a metal to metal seal with thecasing string which may be desirable for use in certain high temperatureand/or high pressure subterranean operations where the effectiveness ofan elastomer seal member may be reduced. Additionally, the degradationof extrusion prevention ring 346 may be less than the degradation of theseal members under such extreme conditions, resulting in a longerlasting liner hanger which may reduce the costs and improve theefficiency of the subterranean operation.

Embodiments disclosed herein include:

A. A liner hanger including an elongate body; a first groove in theelongate body; a first extrusion prevention ring disposed about theelongate body and selectively deformable between a first configuration,where the first extrusion prevention ring is moveable along the lengthof the elongate body, and a second configuration, where the firstextrusion prevention ring is deformed to be received within the firstgroove; and a seal member disposed about the elongate body and adjacentto the first extrusion prevention ring when the first extrusionprevention ring is in the second configuration, the first extrusionprevention ring configured to prevent movement of the seal member alongthe length of the elongate body.

B. A method for coupling a liner to a casing string of a wellboreincluding coupling a liner hanger to a liner. The liner hanger includesan elongate body; a first groove in the elongate body; a first extrusionprevention ring disposed about the elongate body and selectivelydeformable between a first configuration, where the first extrusionprevention ring is moveable along the length of the elongate body, and asecond configuration, where the first extrusion prevention ring isdeformed to be received within the groove; and a seal member disposedabout the elongate body and adjacent to the first extrusion preventionring when the first extrusion prevention ring is in the secondconfiguration, the first extrusion prevention ring configured to preventmovement of the seal member along the length of the elongate body. Themethod further includes lowering the liner and the liner hanger into awellbore through a casing string; and expanding the liner hanger suchthat the seal member is in contact with the casing string.

C. A system for performing subterranean operations including a linerhanger positioned within a casing string of a wellbore and a linercoupled to the liner hanger. The liner hanger includes an elongate body;a groove in the elongate body; a first extrusion prevention ringdisposed about the elongate body and selectively deformable between afirst configuration, where the first extrusion prevention ring ismoveable along the length of the elongate body, and a secondconfiguration, where the first extrusion prevention ring is deformed tobe received within the first groove; and a seal member disposed aboutthe elongate body and adjacent to the first extrusion prevention ringwhen the first extrusion prevention ring is in the second configuration,the first extrusion prevention ring configured to prevent movement ofthe seal member along the length of the elongate body.

Each of embodiments A, B, and C may have one or more of the followingadditional elements in any combination: Element 1: wherein a height ofthe first extrusion prevention ring is based on an outer diameter of theseal member. Element 2: wherein a surface of the first extrusionprevention ring is textured. Element 3: the elongate body is selectivelydeformable from a first configuration, where the elongate body ismoveable along a casing string of a wellbore, and a second configurationwhere the elongate body is expanded such that the seal member is incontact with the casing string; and the first extrusion prevention ringis deformable to a third configuration where the first extrusionprevention ring is in contact with the casing string. Element 4: whereinthe first extrusion prevention ring has a flat surface contacting thecasing string. Element 5: wherein a width of the first extrusionprevention ring is based on a weight of a liner attached to the elongatebody. Element 6: wherein a shape of the first groove corresponds to ashape of the first extrusion prevention ring. Element 7: a second groovein the elongate body; and a second extrusion prevention ring disposedabout the elongate body and selectively deformable from a firstconfiguration, where the second extrusion prevention ring is moveablealong the length of the elongate body, and a second configuration, wherethe second extrusion prevention ring is deformed to be received withinthe second groove, the second extrusion prevention ring located adjacentto the seal member on an opposite side of the seal member from the firstextrusion prevention ring.

Although the present disclosure and its advantages have been describedin detail, it should be understood that various changes, substitutionsand alterations can be made herein without departing from the spirit andscope of the disclosure as defined by the following claims. For example,while the embodiment discussed describes a extrusion prevention ringwith a flat top surface, the extrusion prevention ring may also have apointed or spiked top surface and may be made of any suitable materialand in any suitable shape. Additionally, while the liner hanger is shownas being used with drilling equipment, the liner hanger may be used inany suitable subterranean operation. It is intended that the presentdisclosure encompasses such changes and modifications as fall within thescope of the appended claims.

1. A liner hanger, comprising: an elongate body; a first groove in theelongate body; a seal member disposed about the elongate body; and afirst extrusion prevention ring disposed about the elongate body andselectively deformable between a first configuration, and a secondconfiguration; , wherein in the first configuration, the first extrusionprevention ring is movable along the length of the elongate body;wherein in the second configuration, the first extrusion prevention ringis received within the first groove and adjacent to the seal member toprevent movement of the seal member along the length of the elongatebody.
 2. The liner hanger of claim 1, wherein a height of the firstextrusion prevention ring is based on an outer diameter of the sealmember.
 3. The liner hanger of claim 1, wherein a surface of the firstextrusion prevention ring is textured.
 4. The liner hanger of claim 1,wherein: the elongate body is selectively deformable from a firstconfiguration, where the elongate body is moveable along a casing stringof a wellbore, to a second configuration where the elongate body isexpanded such that the seal member is in contact with the casing string;and the first extrusion prevention ring is deformable to a thirdconfiguration where the first extrusion prevention ring is in contactwith the casing string.
 5. The liner hanger of claim 4, wherein thefirst extrusion prevention ring has a flat surface contacting the casingstring.
 6. The liner hanger of claim 1, wherein a width of the firstextrusion prevention ring is based on a weight of a liner attached tothe elongate body.
 7. The liner hanger of claim 1, wherein a shape ofthe first groove corresponds to a shape of the first extrusionprevention ring.
 8. The liner hanger of claim 1, further comprising: asecond groove in the elongate body; and a second extrusion preventionring disposed about the elongate body and selectively deformable from afirst configuration, where the second extrusion prevention ring ismoveable along the length of the elongate body, to a secondconfiguration, where the second extrusion prevention ring is deformed tobe received within the second groove, the second extrusion preventionring located adjacent to the seal member on an opposite side of the sealmember from the first extrusion prevention ring.
 9. A method forcoupling a liner to a casing string of a wellbore, comprising: couplinga liner hanger to a liner, the liner hanger including: an elongate body;a first groove in the elongate body; a seal member disposed about theelongate body; and a first extrusion prevention ring disposed about theelongate body and selectively deformable between a first configuration;wherein in the first configuration, the first extrusion prevention ringis movable along the length of the elongate body; wherein in the secondconfiguration, the first extrusion prevention ring is received withinthe first groove and adjacent to the seal member to prevent movement ofthe seal member along the length of the elongate body; lowering theliner and the liner hanger into a wellbore through a casing string; andexpanding the liner hanger such that the seal member is in contact withthe casing string.
 10. The method of claim 9, wherein a height of thefirst extrusion prevention ring is based on an outer diameter of theseal member.
 11. The method of claim 9, wherein a surface of the firstextrusion prevention ring is textured.
 12. The method of claim 9,wherein the first extrusion prevention ring is deformable to a thirdconfiguration where the first extrusion prevention ring is in contactwith the casing string of a wellbore.
 13. The method of claim 9, whereina shape of the first groove corresponds to a shape of the firstextrusion prevention ring.
 14. The method of claim 9, wherein the linerhanger further includes: a second groove in the elongate body; and asecond extrusion prevention ring disposed about the elongate body andselectively deformable from a first configuration, where the secondextrusion prevention ring is moveable along the length of the elongatebody, to a second configuration, where the second extrusion preventionring is deformed to be received within the second groove, the secondextrusion prevention ring located adjacent to the seal member on anopposite side of the seal member from the first extrusion preventionring.
 15. A system for performing subterranean operations, comprising: aliner hanger positioned within a casing string of a wellbore, the linerhanger including: an elongate body; a first groove in the elongate body;a seal member disposed about the elongate body; and a first extrusionprevention ring disposed about the elongate body and selectivelydeformable between a first configuration and a second configuration;wherein in the first configuration, the first extrusion prevention ringis movable along the length of the elongate body; wherein in the secondconfiguration, the first extrusion prevention ring is received withinthe first groove and adjacent to the seal member to prevent movement ofthe seal member along the length of the elongate body; and a linercoupled to the liner hanger.
 16. The system of claim 15, wherein aheight of the first extrusion prevention ring is based on an outerdiameter of the seal member.
 17. The system of claim 15, wherein asurface of the first extrusion prevention ring is textured.
 18. Thesystem of claim 15, wherein: the elongate body is selectively deformablefrom a first configuration, where the elongate body is moveable along acasing string of a wellbore, to a second configuration where theelongate body is expanded such that the seal member is in contact withthe casing string; and the first extrusion prevention ring is deformableto a third configuration where the first extrusion prevention ring is incontact with the casing string.
 19. The system of claim 18, wherein thefirst extrusion prevention ring has a flat surface contacting the casingstring.
 20. The system of claim 15, where in the liner hanger furtherincludes: a second groove in the elongate body; and a second extrusionprevention ring disposed about the elongate body and selectivelydeformable from a first configuration, where the second extrusionprevention ring is moveable along the length of the elongate body, to asecond configuration, where the second extrusion prevention ring isdeformed to be received within the second groove, the second extrusionprevention ring located adjacent to the seal member on an opposite sideof the seal member from the first extrusion prevention ring.